Chester Nez died (4-6-2014)

Last of the Navajo code-talkers of World War II.
They transmitted radio messages in Navajo, a language which could not be understood by the enemy.
Things I didn't know:
Other languages were used this way: Choctaw, Cherokee and Comanche in WWI; and Hopi, Mohawk and Tlingit in WWII. And Cree, by the Canadians.
There was a word-alphabet (of the "Alpha-Bravo-Charlie" kind), but based on initials of English words, which were then translated:
A ant wol-la-chee
B bear shush
C cat moasi
etc.
Words for modern warfare devices used a lot of animal metaphors. (I don't know if this is how ordinary civilian Navajo named them, or if it was to avoid too-obvious English loanwords.)
So an example:
Original: Request artillery and tank fire at 123B, Company E move 50 yards left flank of Company D.
Coded: Ask for many big guns and tortoise fire at 123 Bear tail drop Mexican ear mouse owl victor elk 50 yards left flank ocean fish Mexican deer
Then translate word by word into Navajo.
(I'm not sure I follow that in detail, but you get the idea.
Crystal's source is _Navajo Weapon_ by Sally McLain (1994).)